In a large bowl, whisk together flours, turmeric, salt and baking powder. Add butter and use your fingers to quickly rub them into the flour mixture until it resembles coarse meal with a few larger lumps of butter visible. Drizzle oil over the top and toss to combine.

In a small bowl, whisk together cold water and egg yolk. Add to the flour mixture and stir until the dough begins to come together. Knead dough just a few times to bring it together. Flatten dough into a disc, wrap well in plastic wrap and place in the refrigerator to chill for at least 1 hour.

To prepare the filling

Meanwhile, in a medium skillet over medium heat, cook ground sirloin, scallions and chile pepper, stirring to crumble beef, until cooked through, about 4 to 6 minutes. Add breadcrumbs, beef broth, thyme, salt and turmeric, tossing well to combine. Remove from the heat and set aside to cool.

Preheat oven to 400 degrees.

Remove dough from the refrigerator and unwrap - evenly divide into 6 pieces. On a lightly floured surface, roll each portion of dough into a 3/8" thick 6" round. Place about 1/4 cup filling on half of the top of each circle, leaving about a 1/4" border. For each circle, fold the dough over the filling to seal it inside, crimping the edges with a fork. Place on a large baking sheet lined with parchment paper.

Place sheet into the oven and bake until golden brown, about 30 to 40 minutes. Remove and let cool slightly before serving.